Shock absorber



' July 29, 1930.A A, A Down E-r AL 1,711,879

SHOCK ABSORBER Filed 0G13. ll, 1927 Patented July 29, 1930 UNITED STATESALBERT A. DOWD AND SHOCK ABSORBER Application led October 11,. 1927.Serial No. 225,453.

This invention relates to improvements in shock absorbers and the chiefpurpose thereof is to provide a shock absorber suitable for applicationto a motor vehicle to absorb the road shocks incident to travel thereof.

One object of the invention is to provide such a structure of simplesturdy character wherein improved means is employed to cushion theslight shocks in conjunction with other means operable to cushion thegreater shocks.

A meritorious feature lies in the provision of such a structure whereina compression chamber is employed which is partially illed with a liquidmedium and which has an air dome wherein air is trapped by the liquidand mechanism is used which exerts a pressure upon the liquid in thecompression chamber which in turn serves to compress the air in the airdome to cushion the slight shocks incident to road travel and the liquiditself is exhausted through a restricted opening to absorb the greatershocks incident to travelof the vehicle.

The several meritorious features of our improved structure, togetherwith other advantages and objects thereof, will more fully appear fromthe following description of the illustrative embodiment shown in theaccom- 3 panying drawing and defined in the appended claims.

The gure of the drawing is a vertical sectional view through ourimproved structure, illustratin the working parts thereof.

Shock a sorbers of this general type are commonly used on motor vehiclesand the compression chamber or receptacle is secured to one part of thevehicle such as the frame, and a connection leads from an operatingmember to another relatively moving part of the vehicle such as .theaxle so as to absorb the rebound of the body as the car travels over theroad. To this extent our invention resembles others.

We provide a reservoir or lcasing,.which is here indicated as 10,provided with a removable cap 12 through wh'ich liuid4l may be pouredinto the casing. This casing is divided into two compartments, 14 and16, by a HAROLD E. JACKSON, OF DETROIT, MICHIGAN; SAID DOWD ASSIGNOR TOSAID JACKSON compartment 14. When the pressure exceeds partition 18.rl`he partition is shaped as at PATENT OFFICE 2O to provide a cylinderopening at one end into the compartment 14 andv at the other end intothe compartment 16. A piston 22 1s operatively disposed within thecylinder. The head of the piston is drilled out as at 24 55 to providefluid p assageways controlled by a ball check valve 26 which is carriedwithin a cage 28 that is perforated as indicated at 30.

A spring 32 holds the piston toward one end of the cylinder. Anoperating member 34, mounted upon a shaft 36, which is coupled to an arm38, is employed to force the piston against the tension of the springstoward the compartment 16.

40 indicates a boss'extending through com- 55 partment 16 through whicha supportingrod may be passed. 42 indicates a screw-threaded cylinderplug. The two compartments communicate with each other through arestricted passageway 44, the opening through which is regulated by anadjustable member 46 which is bored out and carries a relief valve 48held upwardly.' by a spring 50 to close an opening 52 having outlets 54.In the upper dome-shaped portion of the compartment 16 there is a ballcheck air valve 56 held upwardly by a spring 58 to close an inlet 60. f

In operation, upon the downward movement of the car body, the pistontravels outwardly under the impulse of the spring 32 and the ball checkvalve 26 opens, permitting the ilow of liquid from compartment 4 intocompartment 16. On the recoil the piston is forced toward thecompartment 16 85 against the tension of the spring 32 and against thepressure of the fluid within such compartment 16, 'first acting tocompress the air in the upper portion of compartment 16 above the liquidlevel to absorb the small or 9 light shocks incident to travel of thecar over the road and then acting to force the liquid through therestricted passageway 44 into the a certain predetermined point,the`valve 48 95 opens and increases the communicating passageway leadingfrom chamber 16 into chamber 14.

What we claim is:

1. A shock absorber comprising a reservoir 1m divided vertically .by apartition into two compartments, a cylinder extending through saidpartition and opening into each com artment, a piston reciprocable inthe cylin er, a check valve in the head of the piston, a restrictedvalve controlled opening through the partition, a spring urging thepiston in one direction in t e cylinder, an operating member to urge thepiston in the o posite direction in the cylinder, and a liqui medium inthe reservoir submerging the cylinder, and an air pocket above theliquid medium in that compartment toward which the piston is urged bythe operating member.

2. A shock absorber having a reservoir divided-into two compartments onebeing a compression compartment and the other a reservoir compartment, acylinder open at one end into one compartment and at the opposite endinto the other compartment, a working piston in the cylinder, anoperating connection engaging the piston to move it through thecylinder, a check valve separating the two compartments adapted to closewhen the piston is being driven by the operatin connection to exert apressure upon the liquid in the compression compartment and to open whenthe piston is traveling in the opposite direction to admit liquidthereinto, and a restricted passageway leading from the compressioncompartment to the other to permit exhaust of liquid from thecompression com ,artment into the reservoir compartment an meansextending through the non-compression compartment and the liquid thereinadjustable exteriorly the reservoir to vary the extent of the passagewayleading from the compression compartment@ 3. A shock absorber having areservoir divided into two compartments, a cylinder o n at one 4end intoone compartment and at tlie3 opposite end into the other compartment, aWorking piston in the cylinder, an operating connection engaging thepiston to move it through the c linder, a check valve in the piston adate to close when the piston is ing urge through the cylinder by theoperating connection and to open when the piston is traveling throughthe cylinder in the opposite direction, a restricted passageway leadingfrom one compartment to the other and means associated therewithyieldable under pressure to increase the opening leading from onecompartment to the other.

4. A shock absorber comprising a reservoir divided into two compartmentscommunicating through a restricted passageway, a cylinder open into eachcompartment, a liquid medium in the reservo'ir submerging the cylinder,a working piston in the cylinder, and an o rating connection engagingthe piston to drive the same through the cylinder against the fluidpressure in the one compartment forcing liquid therefrom through the re-'68 stricted passageway into the other compartthrough the sai ment, anda. valve controlled opening through the piston separating thecompartments to permit the passage of liquid from one to the other inthe opposite direction when the piston is moving in the oppositedirection.

5. A shock absorber comprising a reservoir divided into two compartmentscommunicating through a restricted passageway, a cylinder open at oneend into one compartment and open at the other end into the othercompartment, a liquid medium in the reservoir one compartment having anair space above the liquid medium therein, a piston operativel disposedin the cylinder, an operating mem er engaging the piston to drive itthrough the cylinder toward the compartment provided with the air spaceand counter the fluid pressure therein. n

6. A shock absorber comprising a reservoir divided into two compartmentscommunicating through a restricted passageway, a cylinder open at oneend into one compartment and open at the other end into the othercompartment, a working piston in the cylinder, an operating memberengaging the piston to drive itthrough the cylinder toward one of thecompartments, a liquid medium in said compartment to resist the movementof the piston thereinto, an air space in said compartment above theliquid medium and a pair of communicating check valves between saidcompartments below the liquid level, one opening into one com artmentand the other opening into the ot er compartment.

7. A shock absorber having two compartments communicating through arestricted passageway, a cylinder openin at one end into one compartmentand at t e other end into the other compartment, a liquid mediumsubmerging the cylinder in each compartment, one compartment providedwith an air dome above the liquid medium, an air inlet check valve insaid air dome, a working iston in the cylinder, a check -valvecontrolled by the piston, and an operating member engaging the piston todrive it through the cylin er toward the compartment provided with theair dome to force liquid therefrom through the restricted passagewayinto the other compartment.

8. A shock absorber comprising a reservoir divided into two compartmentscommunieating through a valve controlled passageway adapted to permitlow of liquid from one compartment into the other, a cylinder openinginto each compartment, a liquid medium in one compartment, an air pocketin said compartment closed 0H by said liquid medlum, a piston disposedwithin the cylinder, and operating mechanism coupled with the piston toactuate it to compress the liquid 1n said compartment against theresistance of the air in the air tpocket t'o exhaust said liquid valvecontrolled passagelit dium, a cylinder opening into each compart-l ment,a piston operatively disposed in said cylinder t0 be actuated tocompress the liquid medium in the one compartment against vthe air insaid air pocket and to force the liquid from said compartment into theother compartment throu h said restricted liquid passageway, sai pistonprovided with a valve controlled flow passageway through which liquidmay pass in the reverse direction, and means adjustable exteriorl of thereservoir and extending through t e wall thereof and through the liquid1n one compartment to regulate the extent of the passageway leading fromthe other compartment.

In testimony whereof, we, ALBERT A. Down and Hanoi-.n E. JACKSON signthis specication.

ALBERT A. DOWD.

HAROLD E. JACKSON.

